Faraday was an excellent experimentalist who conveyed his ideas in clear and simple language; his mathematical abilities, however, did not extend as far as trigonometry and were limited to the simplest algebra. James Clerk Maxwell took the work of Faraday and others and summarized it in a set of equations which is accepted as the basis of all modern theories of electromagnetic phenomena. On Faraday's uses of lines of force, Maxwell wrote that they show Faraday "to have been in reality a mathematician of a very high order – one from whom the mathematicians of the future may derive valuable and fertile methods."[3] The SI unit of capacitance is named in his honour: the farad.

Albert Einstein kept a picture of Faraday on his study wall, alongside pictures of Isaac Newton and James Clerk Maxwell.[4] Physicist Ernest Rutherford stated, "When we consider the magnitude and extent of his discoveries and their influence on the progress of science and of industry, there is no honour too great to pay to the memory of Faraday, one of the greatest scientific discoverers of all time."[5]

Personal life

Early life

"How fortunate for civilization, that Beethoven, Michelangelo, Galileo and Faraday were not required by law to attend schools where their total personalities would have been operated upon to make them learn acceptable ways of participating as members of “the group."

Michael Faraday was born on 22 September 1791 in Newington Butts,[7] which is now part of the London Borough of Southwark but was then a suburban part of Surrey.[8] His family was not well off. His father, James, was a member of the Glassite sect of Christianity. James Faraday moved his wife and two children to London during the winter of 1790 from Outhgill in Westmorland, where he had been an apprentice to the village blacksmith.[9] Michael was born in the autumn of that year. The young Michael Faraday, who was the third of four children, having only the most basic school education, had to educate himself.[10]

At the age of 14 he became an apprentice to George Riebau, a local bookbinder and bookseller in Blandford Street.[11] During his seven-year apprenticeship Faraday read many books, including Isaac Watts's The Improvement of the Mind, and he enthusiastically implemented the principles and suggestions contained therein.[12] He also developed an interest in science, especially in electricity. Faraday was particularly inspired by the book Conversations on Chemistry by Jane Marcet.[13][14]

Adult life

Portrait of Faraday in his late thirties, ca. 1826

In 1812, at the age of 20 and at the end of his apprenticeship, Faraday attended lectures by the eminent English chemist Humphry Davy of the Royal Institution and the Royal Society, and John Tatum, founder of the City Philosophical Society. Many of the tickets for these lectures were given to Faraday by William Dance, who was one of the founders of the Royal Philharmonic Society. Faraday subsequently sent Davy a 300-page book based on notes that he had taken during these lectures. Davy's reply was immediate, kind, and favourable. In 1813, when Davy damaged his eyesight in an accident with nitrogen trichloride, he decided to employ Faraday as an assistant. Coincidentally one of the Royal Institution's assistants, John Payne, was sacked and Sir Humphry Davy had been asked to find a replacement; thus he appointed Faraday as Chemical Assistant at the Royal Institution on 1 March 1813.[1] Very soon Davy entrusted Faraday with the preparation of nitrogen trichloride samples, and they both were injured in an explosion of this very sensitive substance.[15]

Michael Faraday, ca. 1861, aged about 70.

In the class-based English society of the time, Faraday was not considered a gentleman. When Davy set out on a long tour of the continent in 1813–15, his valet did not wish to go, so instead, Faraday went as Davy's scientific assistant and was asked to act as Davy's valet until a replacement could be found in Paris. Faraday was forced to fill the role of valet as well as assistant throughout the trip. Davy's wife, Jane Apreece, refused to treat Faraday as an equal (making him travel outside the coach, eat with the servants, etc.), and made Faraday so miserable that he contemplated returning to England alone and giving up science altogether. The trip did, however, give him access to the scientific elite of Europe and exposed him to a host of stimulating ideas.[1]

Faraday married Sarah Barnard (1800–1879) on 12 June 1821.[16] They met through their families at the Sandemanian church, and he confessed his faith to the Sandemanian congregation the month after they were married. They had no children.[7]

Faraday was a devout Christian; his Sandemanian denomination was an offshoot of the Church of Scotland. Well after his marriage, he served as deacon and for two terms as an elder in the meeting house of his youth. His church was located at Paul's Alley in the Barbican. This meeting house relocated in 1862 to Barnsbury Grove, Islington; this North London location was where Faraday served the final two years of his second term as elder prior to his resignation from that post.[17][18] Biographers have noted that "a strong sense of the unity of God and nature pervaded Faraday's life and work."[19]

Later life

Three Fellows of the Royal Society offering the presidency to Faraday, 1857

Faraday suffered a nervous breakdown in 1839 but eventually returned to his investigations into electromagnetism.[26] In 1848, as a result of representations by the Prince Consort, Faraday was awarded a grace and favour house in Hampton Court in Middlesex, free of all expenses and upkeep. This was the Master Mason's House, later called Faraday House, and now No. 37 Hampton Court Road. In 1858 Faraday retired to live there.[27]

Having provided a number of various service projects for the British government, when asked by the government to advise on the production of chemical weapons for use in the Crimean War (1853–1856), Faraday refused to participate citing ethical reasons.[28]

Scientific achievements

Chemistry

Equipment used by Faraday to make glass on display at the Royal Institution in London

Faraday's earliest chemical work was as an assistant to Humphry Davy. Faraday was specifically involved in the study of chlorine; he discovered two new compounds of chlorine and carbon. He also conducted the first rough experiments on the diffusion of gases, a phenomenon that was first pointed out by John Dalton. The physical importance of this phenomenon was more fully revealed by Thomas Graham and Joseph Loschmidt. Faraday succeeded in liquefying several gases, investigated the alloys of steel, and produced several new kinds of glass intended for optical purposes. A specimen of one of these heavy glasses subsequently became historically important; when the glass was placed in a magnetic field Faraday determined the rotation of the plane of polarisation of light. This specimen was also the first substance found to be repelled by the poles of a magnet.

Faraday invented an early form of what was to become the Bunsen burner, which is in practical use in science laboratories around the world as a convenient source of heat.[30][31] Faraday worked extensively in the field of chemistry, discovering chemical substances such as benzene (which he called bicarburet of hydrogen) and liquefying gases such as chlorine. The liquefying of gases helped to establish that gases are the vapours of liquids possessing a very low boiling point and gave a more solid basis to the concept of molecular aggregation. In 1820 Faraday reported the first synthesis of compounds made from carbon and chlorine, C2Cl6 and C2Cl4, and published his results the following year.[32][33][34] Faraday also determined the composition of the chlorine clathrate hydrate, which had been discovered by Humphry Davy in 1810.[35][36] Faraday is also responsible for discovering the laws of electrolysis, and for popularizing terminology such as anode, cathode, electrode, and ion, terms proposed in large part by William Whewell.[37]

Faraday was the first to report what later came to be called metallic nanoparticles. In 1847 he discovered that the optical properties of gold colloids differed from those of the corresponding bulk metal. This was probably the first reported observation of the effects of quantum size, and might be considered to be the birth of nanoscience.[38]

Electricity and magnetism

Faraday is best known for his work regarding electricity and magnetism. His first recorded experiment was the construction of a voltaic pile with seven ha'penny coins, stacked together with seven disks of sheet zinc, and six pieces of paper moistened with salt water. With this pile he decomposed sulfate of magnesia (first letter to Abbott, 12 July 1812).

In 1821, soon after the Danish physicist and chemist Hans Christian Ørsted discovered the phenomenon of electromagnetism, Davy and British scientist William Hyde Wollaston tried, but failed, to design an electric motor.[2] Faraday, having discussed the problem with the two men, went on to build two devices to produce what he called "electromagnetic rotation". One of these, now known as the homopolar motor, caused a continuous circular motion that was engendered by the circular magnetic force around a wire that extended into a pool of mercury wherein was placed a magnet; the wire would then rotate around the magnet if supplied with current from a chemical battery. These experiments and inventions formed the foundation of modern electromagnetic technology. In his excitement, Faraday published results without acknowledging his work with either Wollaston or Davy. The resulting controversy within the Royal Society strained his mentor relationship with Davy and may well have contributed to Faraday's assignment to other activities, which consequently prevented his involvement in electromagnetic research for several years.[40][41]

One of Faraday's 1831 experiments demonstrating induction. The liquid battery (right) sends an electric current through the small coil (A). When it is moved in or out of the large coil (B), its magnetic field induces a momentary voltage in the coil, which is detected by the galvanometer (G).

From his initial discovery in 1821, Faraday continued his laboratory work, exploring electromagnetic properties of materials and developing requisite experience. In 1824, Faraday briefly set up a circuit to study whether a magnetic field could regulate the flow of a current in an adjacent wire, but he found no such relationship.[42] This experiment followed similar work conducted with light and magnets three years earlier that yielded identical results.[43][44] During the next seven years, Faraday spent much of his time perfecting his recipe for optical quality (heavy) glass, borosilicate of lead,[45] which he used in his future studies connecting light with magnetism.[46] In his spare time, Faraday continued publishing his experimental work on optics and electromagnetism; he conducted correspondence with scientists whom he had met on his journeys across Europe with Davy, and who were also working on electromagnetism.[47] Two years after the death of Davy, in 1831, he began his great series of experiments in which he discovered electromagnetic induction, recording in his laboratory diary on 28 October 1831 he was; "making many experiments with the great magnet of the Royal Society".[48]

A diagram of Faraday's iron ring-coil apparatus

Built in 1831, the Faraday disk was the first electric generator. The horseshoe-shaped magnet (A) created a magnetic field through the disk (D). When the disk was turned, this induced an electric current radially outward from the center toward the rim. The current flowed out through the sliding spring contact m, through the external circuit, and back into the center of the disk through the axle.

Faraday's breakthrough came when he wrapped two insulated coils of wire around an iron ring, and found that upon passing a current through one coil a momentary current was induced in the other coil.[2] This phenomenon is now known as mutual induction.[49] The iron ring-coil apparatus is still on display at the Royal Institution. In subsequent experiments, he found that if he moved a magnet through a loop of wire an electric current flowed in that wire. The current also flowed if the loop was moved over a stationary magnet. His demonstrations established that a changing magnetic field produces an electric field; this relation was modelled mathematically by James Clerk Maxwell as Faraday's law, which subsequently became one of the four Maxwell equations, and which have in turn evolved into the generalization known today as field theory.[50] Faraday would later use the principles he had discovered to construct the electric dynamo, the ancestor of modern power generators and the electric motor.[51]

In 1832, he completed a series of experiments aimed at investigating the fundamental nature of electricity; Faraday used "static", batteries, and "animal electricity" to produce the phenomena of electrostatic attraction, electrolysis, magnetism, etc. He concluded that, contrary to the scientific opinion of the time, the divisions between the various "kinds" of electricity were illusory. Faraday instead proposed that only a single "electricity" exists, and the changing values of quantity and intensity (current and voltage) would produce different groups of phenomena.[2]

Near the end of his career, Faraday proposed that electromagnetic forces extended into the empty space around the conductor.[50] This idea was rejected by his fellow scientists, and Faraday did not live to see the eventual acceptance of his proposition by the scientific community. Faraday's concept of lines of flux emanating from charged bodies and magnets provided a way to visualize electric and magnetic fields; that conceptual model was crucial for the successful development of the electromechanical devices that dominated engineering and industry for the remainder of the 19th century.

Diamagnetism

Faraday holding a type of glass bar he used in 1845 to show magnetism affects light in dielectric material.[52]

In 1845, Faraday discovered that many materials exhibit a weak repulsion from a magnetic field: a phenomenon he termed diamagnetism.[53]

Faraday also discovered that the plane of polarization of linearly polarized light can be rotated by the application of an external magnetic field aligned with the direction in which the light is moving. This is now termed the Faraday effect.[50] In Sept 1845 he wrote in his notebook, "I have at last succeeded in illuminating a magnetic curve or line of force and in magnetising a ray of light".[54]

Later on in his life, in 1862, Faraday used a spectroscope to search for a different alteration of light, the change of spectral lines by an applied magnetic field. The equipment available to him was, however, insufficient for a definite determination of spectral change. Pieter Zeeman later used an improved apparatus to study the same phenomenon, publishing his results in 1897 and receiving the 1902 Nobel Prize in Physics for his success. In both his 1897 paper[55] and his Nobel acceptance speech,[56] Zeeman made reference to Faraday's work.

Faraday cage

In his work on static electricity, Faraday's ice pail experiment demonstrated that the charge resided only on the exterior of a charged conductor, and exterior charge had no influence on anything enclosed within a conductor. This is because the exterior charges redistribute such that the interior fields emanating from them cancel one another. This shielding effect is used in what is now known as a Faraday cage.[50]

Beyond his scientific research into areas such as chemistry, electricity, and magnetism at the Royal Institution, Faraday undertook numerous, and often time-consuming, service projects for private enterprise and the British government. This work included investigations of explosions in coal mines, being an expert witness in court, and along with two engineers from Chance Brothers c.1853, the preparation of high-quality optical glass, which was required by Chance for its lighthouses. In 1846, together with Charles Lyell, he produced a lengthy and detailed report on a serious explosion in the colliery at Haswell County Durham, which killed 95 miners. Their report was a meticulous forensic investigation and indicated that coal dust contributed to the severity of the explosion. The report should have warned coal owners of the hazard of coal dust explosions, but the risk was ignored for over 60 years until the Senghenydd Colliery Disaster of 1913.

Lighthouse lantern room from mid-1800s

As a respected scientist in a nation with strong maritime interests, Faraday spent extensive amounts of time on projects such as the construction and operation of lighthouses and protecting the bottoms of ships from corrosion. His workshop still stands at Trinity Buoy Wharf above the Chain and Buoy Store, next to London's only lighthouse where he carried out the first experiments in electric lighting for lighthouses.[59]

Faraday assisted with the planning and judging of exhibits for the Great Exhibition of 1851 in London. He also advised the National Gallery on the cleaning and protection of its art collection, and served on the National Gallery Site Commission in 1857.[61][62]

Education was another of Faraday's areas of service; he lectured on the topic in 1854 at the Royal Institution, and in 1862 he appeared before a Public Schools Commission to give his views on education in Great Britain. Faraday also weighed in negatively on the public's fascination with table-turning, mesmerism, and seances, and in so doing chastised both the public and the nation's educational system.[63]

Before his famous Christmas lectures, Faraday delivered chemistry lectures for the City Philosophical Society from 1816 to 1818 in order to refine the quality of his lectures.[64] Between 1827 and 1860 at the Royal Institution in London, Faraday gave a series of nineteen Christmas lectures for young people, a series which continues today. The objective of Faraday's Christmas lectures was to present science to the general public in the hopes of inspiring them and generating revenue for the Royal Institution. They were notable events on the social calendar among London's gentry. Over the course of several letters to his close friend Benjamin Abbott, Faraday outlined his recommendations on the art of lecturing: Faraday wrote "a flame should be lighted at the commencement and kept alive with unremitting splendour to the end".[65] His lectures were joyful and juvenile, he delighted in filling soap bubbles with various gasses (in order to determine whether or not they are magnetic) in front of his audiences and marveled at the rich colors of polarized lights, but the lectures were also deeply philosophical. In his lectures he urged his audiences to consider the mechanics of his experiments: "you know very well that ice floats upon water ... Why does the ice float? Think of that, and philosophise".[66] His subjects consisted of Chemistry and Electricity, and included: 1841 The Rudiments of Chemistry, 1843 First Principles of Electricity, 1848 The Chemical History of a Candle, 1851 Attractive Forces, 1853 Voltaic Electricity, 1854 The Chemistry of Combustion, 1855 The Distinctive Properties of the Common Metals, 1857 Static Electricity, 1858 The Metallic Properties, 1859 The Various Forces of Matter and their Relations to Each Other.[67]

A Royal Society of Artsblue plaque, unveiled in 1876, commemorates Faraday at 48 Blandford Street in London's Marylebone district.[72] From 1991 until 2001, Faraday's picture featured on the reverse of Series E £20 banknotes issued by the Bank of England. He was portrayed conducting a lecture at the Royal Institution with the magneto-electric spark apparatus.[73] In 2002, Faraday was ranked number 22 in the BBC's list of the 100 Greatest Britons following a UK-wide vote.[74]

The Faraday Institute for Science and Religion derives its name from the scientist, who saw his faith as integral to his scientific research. The logo of the Institute is also based on Faraday's discoveries. It was created in 2006 by a $2,000,000 grant from the John Templeton Foundation to carry out academic research, to foster understanding of the interaction between science and religion, and to engage public understanding in both these subject areas.[75][76]

Faraday's books, with the exception of Chemical Manipulation, were collections of scientific papers or transcriptions of lectures.[81] Since his death, Faraday's diary has been published, as have several large volumes of his letters and Faraday's journal from his travels with Davy in 1813–1815.

^For a concise account of Faraday's life including his childhood, see pages 175–83 of EVERY SATURDAY: A JOURNAL OF CHOICE READING, Vol III published at Cambridge in 1873 by Osgood & Co.

^The implication is that James discovered job opportunities elsewhere through membership of this sect. James joined the London meeting house on 20 February 1791, and moved his family shortly thereafter. See Cantor, pp. 57–8.

^The register at St. Faith-in-the-Virgin near St. Paul's Cathedral, records 12 June as the date their licence was issued. The witness was Sarah's father, Edward. Their marriage was 16 years prior to the Marriage and Registration Act of 1837. See Cantor, p. 59.

^"The Birth of Nanotechnology". Nanogallery.info. 2006. Retrieved 25 July 2007. Faraday made some attempt to explain what was causing the vivid coloration in his gold mixtures, saying that known phenomena seemed to indicate that a mere variation in the size of gold particles gave rise to a variety of resultant colors.

^Faraday's initial induction lab work occurred in late November 1825. His work was heavily influenced by the ongoing research of fellow European scientists Ampere, Arago, and Oersted as indicated by his diary entries. Cantor, pp. 235–44.